Tachometer

[gberger]

Hello all,

My 1980 300 SD Turbo Diesel 116.120 has a Non-Functioning Tachometer.   Could someone give me some suggestions or path to follow to fix this?

Please advise,

Greg Berger

[oscar]

Hi Greg,

I'm not 100% on this so I'll see what some of the US fellas come up with, but in previous mentions of problems with the 300sd tacho not working, it's been because of the amplifier.  I can't remember why but I assumed it was a common fault.  Anyway, wait for some real advice before you go and buy another.  I thought there was a way to fix them but again, no idea from me. 

Welcome BTW

http://cgi.ebay.com/ebaymotors/Mercedes-tachometer-amplifier-W116-W123-W126-300SD-300D_W0QQcmdZViewItemQQcategoryZ33679QQihZ005QQitemZ150117138084QQrdZ1QQsspagenameZWD2V

[James R]

Has anyone ever called you Gerhard before ?

[Andrew280SEL]

Mine doesnt work either, so i hope its something simple like the amp.
Thanks for that mr. astronaut Bateman! 

[Andrew280SEL]

I had to replace the coil a while back, but even before then the tacho didnt work...

I'll check the connection. Is it just a pin type plug in?

[gregdeklerk]

Hi Greg, welcome to the forum, from another Greg.

[oscar]

Hey Andrew,

Have a look back thru my old thread HERE  This is for petrol engines only but in the end I believe my faulty tacho was caused by a bad earth in the cluster.  There's a two pin black plug on the back of the tacho which one runs to the coil and I don't know where the other goes.  Have a look at THIS THREAD for tach installation which has lost a few photo links unfortunately but should have the answers of what connects to what. 

The earth for the tacho runs thru the multipin connector behind the oil/temp/fuel combo guage (I believe) and travels by the way of contact between the backing plates of each instrument module.  Simply tightening the screws of these backing plates may fix the tacho, but I'd losen and clean them before calling them fixed just to be safe.

[Nutz]

Hello all,

My 1980 300 SD Turbo Diesel 116.120 has a Non-Functioning Tachometer.   Could someone give me some suggestions or path to follow to fix this?

Please advise,

Greg Berger

Same engine but W123

OM617 Tach and Specs

[Andrew280SEL]

Thanks Pat and Oscar.

This should help immensely 

[WGB]

One thing that can happen to connectors when they get old is that the pins can move in the connector and what looks like an adequate connction has pushed out the back of it's socket and is not connecting well.

This is a possible fault in instrument harnesses especially.

Bill

[SELfor50]

On the subject of Tacho's - do you guys have any good suggestions for a rev meter on my 450SEL?

I'm not talking bout a dodgy monster tacho up high or anything...i just want something that tells me what my engines revving at etc.

Cam.

[oscar]

Are you after a tacho replacement Cam?  Have you  got one at the moment or only a large clock to the left of the speedo?

There's always one one ebay and the odd one that appears on Oz Ebay now and then or part of a complete cluster usually.  Just have to make sure it's from a V8 not a 280.

eg I don't know whether this has a tacho or not.  Worth asking for another pic and what is the cluster from, though you've only got a few hours before this one ends.
http://cgi.ebay.com.au/MERCEDES-BENZ-W116-INSTRUMENT-CLUSTER_W0QQitemZ130106664064QQihZ003QQcategoryZ72454QQrdZ1QQcmdZViewItem

But there's always a few in Germany or US
http://cgi.ebay.com.au/Mercedes-W116-W107-Kombiinstrument-mit-Drehzahlmesser_W0QQitemZ180113095384QQihZ008QQcategoryZ99207QQrdZ1QQcmdZViewItem

If you're after an aftermarket digital tacho I got no idea.

[SELfor50]

Thanks for finding that mate!!

Yeah, currently got the clock on the right hand side...

Not really keen to swap out the whole dash - cause the car only has 148,000 on the clock and any replacement dash i'll get will probably be more than this.

Pretty much just after an aftermarket tacho to tell me the rpm's - thought someone might have done this before and be able to offer advice.

[gregdeklerk]

Thanks for finding that mate!!

Yeah, currently got the clock on the right hand side...

Not really keen to swap out the whole dash - cause the car only has 148,000 on the clock and any replacement dash i'll get will probably be more than this.

Pretty much just after an aftermarket tacho to tell me the rpm's - thought someone might have done this before and be able to offer advice.

You don't need to swap all the instruments! All you need to do is to take out the big clock and replace it with the genuine Tacho and small clock in one, as well as all the other parts to get the genuine tacho to work!

[oscar]

Not dismissing the possibility of an aftermarket setup, certainly if someone's got a suggestion throw it in.


Although I haven't seen a post relate to one before,  I'm sure there's an easy way to rig one up to the coil etc.  However, as one last suggestion look at this old thread below.  As Greg says, you can keep your old speedo and cluster.  You can easily swap the large clock for a combined small clock and tach combination from another cluster.

http://forum.w116.org/mechanicals/installing-tachometer/0/